Beyond immunohaematology: the role of the ABO blood group in human diseases

Review of ABO Expression and Variations based on Transcriptional Regulation of the ABO Blood Group Gene

Background and Summary

We review the transcriptional regulation of ABO expression and discuss variants in the promoter and erythroid cell-specific regulatory region in individuals with weak ABO phenotypes such as Bm, Am, B3, and A3. We also review the molecular mechanisms responsible for variations in ABO expression in development and disease including the cell type-specific expression of ABO during erythroid cell differentiation, and reduction of A- or B-antigens in cancer cells or on red blood cells in patients with leukemia. Although the relationship between ABO blood group antigens and diseases has been characterized, the physiological significance of the ABO blood group system remains unclear.

Key Messages

This review discusses accumulated knowledge of the ABO gene regulation and potential reasons for conservation of ABO during evolution.

Association between blood groups and myocardial injury after non-cardiac surgery: a retrospective cohort study

Blood group is a potential genetic element in coronary artery disease. Nevertheless, the relationship between different ABO blood groups and myocardial injury after non-cardiac surgery (MINS) is poorly understood. This study verified whether ABO blood group is a potential MINS influencing factor. This retrospective cohort study included 1201 patients who underwent elective non-cardiac surgery and a mandatory troponin test on postoperative days 1 and 2 from 2019 to 2020 at a university-affiliated tertiary hospital. The primary outcome was associations between ABO blood groups and MINS, assessed using univariate and multivariate logistic-regression analyses. Path analysis was used to investigate direct and indirect effects between blood group and MINS. MINS incidence (102/1201, 8.5%) was higher in blood-type B patients than in non-B patients [blood-type B: 44/400 (11.0%) vs. non-B: 58/801 (7.2%); adjusted odds ratio = 1.57 (1.03-2.38); p = 0.036]. In the confounding factor model, preoperative hypertension and coronary artery disease medical history were associated with MINS risk [adjusted odds ratio: 2.00 (1.30-3.06), p = 0.002; 2.81 (1.71-4.61), p < 0.001, respectively]. Path analysis did not uncover any mediating role for hypertension, diabetes, or coronary artery disease between blood type and MINS. Therefore, blood-type B is associated with higher MINS risk; potential mediators of this association need to be investigated.

Recipient blood group does not affect hepatocellular carcinoma recurrence after living donor liver transplantation in Korea

PURPOSE

This study assessed whether or not the ABO blood type affects the incidence of HCC recurrence after living donor liver transplantation (LDLT).

METHODS

This retrospective observational study included 856 patients with hepatocellular carcinoma (HCC) who underwent LDLT between January 2006 and December 2016 at the Asan Medical Center.

RESULTS

This study included 324 patients (37.9%) with blood type A, 215 (25.1%) with blood type B, 210 (24.5%) with blood type O, and 107 (12.5%) with blood type AB. ABO-incompatible LT was performed in 136 (15.9%) patients. The independent risk factors for the disease-free survival (DFS) were maximal tumor diameter, microvascular invasion, and Milan criteria. The only independent risk factor for the overall survival (OS) was microvascular invasion. The ABO blood group did not affect the DFS (P = 0.978) or OS (P = 0.261). The DFS according to the ABO blood group did not differ significantly between the ABO-compatible (p = 0.701) and ABO-incompatible LDLT recipients (p = 0.147). The DFS according to the ABO blood group did not differ significantly between patients within the Milan criteria (p = 0.934) and beyond the Milan criteria (p = 0.525). The DFS did not differ significantly between recipients with and without type A blood (p = 0.941).

CONCLUSIONS

This study demonstrated that the ABO blood group system had no prognostic impact on the oncological outcomes of patients undergoing LT for HCC.

Integrating plasma protein-centric multi-omics to identify potential therapeutic targets for pancreatic cancer

BACKGROUND

Deciphering the role of plasma proteins in pancreatic cancer (PC) susceptibility can aid in identifying novel targets for diagnosis and treatment.

METHODS

We examined the relationship between genetically determined levels of plasma proteins and PC through a systemic proteome-wide Mendelian randomization (MR) analysis utilizing cis-pQTLs from multiple centers. Rigorous sensitivity analyses, colocalization, reverse MR, replications with varying instrumental variable selections and additional datasets, as well as subsequent meta-analysis, were utilized to confirm the robustness of significant findings. The causative effect of corresponding protein-coding genes' expression and their expression pattern in single-cell types were then investigated. Enrichment analysis, between-protein interaction and causation, knock-out mice models, and mediation analysis with established PC risk factors were applied to indicate the pathogenetic pathways. These candidate targets were ultimately prioritized upon druggability and potential side effects predicted by a phenome-wide MR.

RESULTS

Twenty-one PC-related circulating proteins were identified in the exploratory phase with no evidence for horizontal pleiotropy or reverse causation. Of these, 11 were confirmed in a meta-analysis integrating external validations. The causality at a transcription level was repeated for neutrophil elastase, hydroxyacylglutathione hydrolase, lipase member N, protein disulfide-isomerase A5, xyloside xylosyltransferase 1. The carbohydrate sulfotransferase 11 and histo-blood group ABO system transferase exhibited high-support genetic colocalization evidence and were found to affect PC carcinogenesis partially through modulating body mass index and type 2 diabetes, respectively. Approved drugs have been established for eight candidate targets, which could potentially be repurposed for PC therapies. The phenome-wide investigation revealed 12 proteins associated with 51 non-PC traits, and interference on protein disulfide-isomerase A5 and cystatin-D would increase the risk of other malignancies.

CONCLUSIONS

By employing comprehensive methodologies, this study demonstrated a genetic predisposition linking 21 circulating proteins to PC risk. Our findings shed new light on the PC etiology and highlighted potential targets as priorities for future efforts in early diagnosis and therapeutic strategies of PC.

Associations Between ABO Blood Groups and Diseases in the Digestive System and Vein

Purpose

The ABO blood type system is crucial for human blood transfusions. However, the relationships between ABO blood groups and diseases in the digestive system and vein have not been elucidated. We investigated the relationships between ABO blood groups and diseases in the digestive system and vein in this study.

Patients and Methods

A retrospective study on a Chinese population, including 1432 Crohn's disease (CD), 416 ulcerative colitis (UC), 1140 stomach cancer (SC), 841 colorectal cancer (CRC), 384 pancreatic cancer (PC), 520 liver cancer (LC), and 563 venous thrombosis (VT) patients, was performed. Furthermore, 896 healthy subjects were enrolled as normal controls (NC) in this study. The demographic characteristics of patients and NC were compared using the unpaired t-test and χ2 test. Multivariate logistic regression model was used to evaluate the association between ABO blood groups and CD and VT.

Results

ABO blood groups distributions in UC, SC, CRC, PC, and LC patients did not differ from that of NC, but CD and VT patients had significant difference of ABO blood group distribution from that of NC (p = 0.015 and p = 0.002, respectively). Patients with CD and VT had considerably lower rates of type O blood (p = 0.011 and p = 0.001, respectively) and significantly higher rates of type AB blood (p = 0.013 and p = 0.022, respectively) than those with NC. Multivariate logistic regression analysis showed the association of CD and VT with non-O blood types was still significant with a higher risk than with blood group O after adjusting for age and gender (OR = 1.355, 95% CI = 1.100-1.670, p = 0.004 and OR = 1.465, 95% CI = 1.131-1.903, p = 0.004, respectively).

Conclusion

ABO blood groups distributions in CD and VT patients significantly differed from that of NC. Non-O blood group could be a new predictor for CD and VT.

Association between ABO and Rh blood groups and Toxoplasma gondii infection: A cross sectional study

We aimed to determine the association between the seropositivity to Toxoplasma gondii and the ABO and Rh blood groups in 2,053 people. ABO and Rhesus blood groups and anti-T. gondii IgG and IgM antibodies were determined using commercially available assays. Of the 2,053 people studied, 171 (8.3%) were positive for anti-T. gondii IgG antibodies. Sixty-five (38.0%) and 36 (21.1%) of these 171 individuals had high anti-T. gondii IgG antibody levels (≥150 IU mL-1) and anti-T. gondii IgM antibodies, respectively. We found the following prevalences of T. gondii infection among the ABO groups: 8.5% in group A, 4.3% in group B, 4.7% in group AB, and 8.9% in group O (P = 0.19). The prevalences of T. gondii infection among Rh groups were: 8.4% in the Rh-positive group and 7.1% in the Rh-negative group (P = 0.58). Logistic regression analysis showed that the frequencies of ABO and Rh blood groups were similar (P > 0.05) among people with positive and negative serology for anti-T. gondii IgG antibodies, with high (≥150 IU mL-1) and lower (<150 IU mL-1) levels of anti-T. gondii IgG antibodies, and with positive and negative serology for anti-T. gondii IgM antibodies. Results does not support an association between T. gondii infection and ABO and Rh blood groups.

ABO blood group and cochlear function: evidence from a large sample size study

OBJECTIVE

The present study investigated the effect of blood group on cochlear function in a large participant sample across different age groups. The study hypothesis was that participants with blood group O would show relatively reduced cochlear function as reflected in otoacoustic emission (OAE) measures.

DESIGN

Data were collected from transient evoked otoacoustic emission (TEOAE), distortion product otoacoustic emission (DPOAE), DPOAE input/output (I/O) function, and spontaneous otoacoustic emission (SOAE) recordings.

STUDY SAMPLE

Four hundred and sixty-three normal hearing adults aged 20-59 years among the four ABO blood groups participated in the study.

RESULTS

TEOAE and DPOAE amplitudes did not reveal significant differences for participants with blood group O compared with participants with non-O blood groups. No significant differences in I/O function categories were found among participants with different blood groups. SOAE prevalence was also not significantly different across blood groups. However, previously reported age and gender differences for OAE variables were confirmed.

CONCLUSIONS

Participants with blood group O were not found to have significantly reduced cochlear function, based on OAE measures. Results from the current study do not support the hypothesis that normal hearing individuals with different ABO blood groups differ in level of cochlear function.

Association of ABO Blood Groups and Obesity in Patients With Diabetes Mellitus in King Abdulaziz University Hospital

BACKGROUND

Differences in the blood, resulting from the presence or absence of antigens corresponding to specific blood types, have indirect implications for susceptibility to diseases. The aim of this study was to examine the association between the ABO type and obesity in patients with diabetes mellitus.

METHODS

This is a cross-sectional observational study that was conducted at King Abdulaziz University Hospital (KAUH) in Jeddah, Saudi Arabia. Data were collected using a simple random method through hospital records during the period between August and September 2022. Patients with type 1 diabetes mellitus (T1DM) and T2DM were included in this study. Binary logistic regression analysis was used to identify the association between blood group and obesity.

RESULTS

A total of 411 patients were involved in this study. More than half of the patients (54.3%; n= 223) are diagnosed with T1DM. O-positive was the most common blood group type among the patients, accounting for 38.6% (n= 161). Only 23.6% (n= 97) of the patients were classified as having normal weight. Around 32.6% (n= 134) of the patients were classified as having the pre-obesity stage. More than one-third of the patients (35.1%; n= 145) were classified as being obese. There was no statistically significant difference between the patients in terms of their blood type group and its association with obesity (p>0.05).

CONCLUSION

Many diabetics are overweight or obese, according to this study. This shows the importance of weight management for diabetes treatment. Many patients were overweight, emphasizing the importance of obesity prevention and diabetes care. Most patients were O-positive, according to blood type tests. Previous research suggests that blood types may be linked to diabetes. However, this study found no significant relationships. More research is needed to understand the complex link between blood types, weight, and diabetes.

ABO blood types may affect transient neurological events after surgical revascularization in patients with moyamoya disease: a retrospective single center study

BACKGROUND

Moyamoya disease (MMD) is a cerebrovascular disease with unknown cause. Patients with MMD disease usually experience transient neurological events (TNEs) after revascularization surgery. This retrospective single-center study was aimed to explore the risk factors of postoperative TNEs after surgical revascularization in patients with MMD.

METHODS

We selected 324 patients who underwent surgical revascularization between January 2017 and September 2022 in our center. The perioperative characteristics of the patients were recorded and the outcome was TNEs after surgery. An analysis of risk factors contributing to postoperative TNEs by using logistic regression model.

RESULTS

Three hundred twelve patients were enrolled, and the incidence of postoperative TNEs was 34% in our study. Males were more likely to suffer from postoperative TNEs (OR = 2.344, p = 0.002). Preoperative ischemic presentation (OR = 1.849, p = 0.048) and intraoperative hypotension (OR = 2.332, p = 0.002) were associated with postoperative TNEs. Compared to patients with blood type O, patients with blood type A (OR = 2.325, p = 0.028), B (OR = 2.239, p = 0.027) and AB (OR = 2.938, p = 0.019) had a significantly higher incidence of postoperative TNEs. A risk prediction model for postoperative TNEs was established, and the established risk prediction area under the receiver operating characteristic curve (ROC) of the model was 0.741.

CONCLUSIONS

Males, preoperative ischemic presentation and intraoperative hypotension were associated with postoperative TNEs. We also found a possible link between postoperative TNEs and ABO blood types after surgical revascularization for moyamoya patients.

Association between Blood Group and Change in Coagulation Factors in Plasma Preparations for Transfusion Purpose at Kisii Teaching and Referral Hospital

Background

Blood component therapy helps in managing patients with reduced hematopoiesis, elevated peripheral destruction of cells, and generalized blood loss (bleeding). Increased prevalence of arterial and venous thrombotic disease linked to the impact of ABO blood group on plasma levels of coagulation glycoprotein is demonstrated by blood group non-O persons.

Objective

This study had a main objective of determining the association between blood group and change in coagulation factors in plasma preparation for transfusion purpose.

Methods

The study employed a longitudinal study design. Factor assay evaluation was done by the use of Erba Mannheim ECL 105 semiautomated coagulation analyzer from India. Thawing meant for consequent coagulation factor analysis and sequential testing of stored cryoprecipitate and fresh frozen plasma was performed by the use of Stericox plasma thawing bath before being analyzed by the coagulation analyzer. Blood group of the collected blood sample in purple EDTA vacutainer was analyzed using blood antisera and a clean white tile, and results were recorded which helped in establishing the association existing between plasma and blood group. The data were fed into Excel and were evaluated by the use of SPSS version 25.

Results

There was no significant association between coagulation factors in fresh frozen plasma and blood group, coagulation factors in cryoprecipitate plasma and blood group of the donors showed that the relationship was not significant with, (r = -0.116, -0.097, 0.007 and 0.047 with p value (0.900, 0.087, 0.096 and 0.096), respectively, which are greater than 0.005 standard alpha value.

Conclusion

This study has shown no significant association existing between blood group and change in coagulation factors in plasma preparations at Kisii Teaching and Referral Hospital.

Haplotype sequence collection of ABO blood group alleles by long-read sequencing reveals putative A1-diagnostic variants

In the era of blood group genomics, reference collections of complete and fully resolved blood group gene alleles have gained high importance. For most blood groups, however, such collections are currently lacking, as resolving full-length gene sequences as haplotypes (ie, separated maternal/paternal origin) remains exceedingly difficult with both Sanger and short-read next-generation sequencing. Using the latest third-generation long-read sequencing, we generated a collection of fully resolved sequences for all 6 main ABO allele groups: ABO∗A1/A2/B/O.01.01/O.01.02/O.02. We selected 77 samples from an ABO genotype data set (n = 25 200) of serologically typed Swiss blood donors. The entire ABO gene was amplified in 2 overlapping long-range polymerase chain reactions (covering ∼23.6 kb) and sequenced by long-read Oxford Nanopore sequencing. For quality validation, 2 samples per ABO group were resequenced using Illumina and Pacific Biosciences technology. All 154 full-length ABO sequences were resolved as haplotypes. We observed novel, distinct sequence patterns for each ABO group. Most genetic diversity was found between, not within, ABO groups. Phylogenetic tree and haplotype network analyses highlighted distinct clades of each ABO group. Strikingly, our data uncovered 4 genetic variants putatively specific for ABO∗A1, for which direct diagnostic targets are currently lacking. We validated A1-diagnostic potential using whole-genome data (n = 4872) of a multiethnic cohort. Overall, our sequencing strategy proved powerful for producing high-quality ABO haplotypes and holds promise for generating similar collections for other blood groups. The publicly available collection of 154 haplotypes will serve as a valuable resource for molecular analyses of ABO, as well as studies about the function and evolutionary history of ABO.

ABO blood group antigens and differential glycan expression: Perspective on the evolution of common human enzyme deficiencies

Enzymes catalyze biochemical reactions and play critical roles in human health and disease. Enzyme variants and deficiencies can lead to variable expression of glycans, which can affect physiology, influence predilection for disease, and/or directly contribute to disease pathogenesis. Although certain well-characterized enzyme deficiencies result in overt disease, some of the most common enzyme deficiencies in humans form the basis of blood groups. These carbohydrate blood groups impact fundamental areas of clinical medicine, including the risk of infection and severity of infectious disease, bleeding risk, transfusion medicine, and tissue/organ transplantation. In this review, we examine the enzymes responsible for carbohydrate-based blood group antigen biosynthesis and their expression within the human population. We also consider the evolutionary selective pressures, e.g. malaria, that may account for the variation in carbohydrate structures and the implications of this biology for human disease.

Association Between ABO Blood Group and Gestational Diabetes Mellitus in Pregnant Women at King Abdulaziz University Hospital: A Retrospective Study

Objective Gestational diabetes mellitus (GDM) can occur during pregnancy. One of the leading causes of it is a hormone produced by the placenta that interferes with glucose absorption and causes glucose buildup in the bloodstream. Genetic variations between ethnicities are believed to be associated with GDM, and there has been some research on the association of ABO blood group with GDM in different populations. However, the results so far are inconsistent, and there is no conclusive evidence on how ABO blood group affects the occurrence of GDM. This study aims to examine the link between ABO blood group and GDM in pregnant women at King Abdulaziz University Hospital. Methodology A retrospective cohort study was conducted on a group of GDM patients between 2019 and 2022 using data collected from the patients' medical records at King Abdulaziz University Hospital. Results The overall prevalence of GDM was high at 74.7%, and the percentage of patients with A, O, B, and AB blood group who had GDM was 42.9%, 41.41%, 12.1%, and 3.59%, respectively. However, there was no significant difference in Rh status or any other clinical characteristic between the participants who had GDM and those who did not have GDM. Conclusion The present findings indicate that blood group is not associated with the development of GDM in this cohort from Saudi Arabia. However, more studies are required in the future to corroborate these findings.

Relationships of ABO and Rhesus blood groups with type 2 diabetes mellitus: a systematic review and meta-analysis

OBJECTIVES

The susceptibility to type 2 diabetes mellitus (T2DM) has been linked to blood type. We aimed to characterize the relationships of the ABO and Rhesus blood groups with T2DM.

METHODS

Literature searches were performed using the Medline, PubMed, Scopus, Cochrane, EMBASE, and Google Scholar databases to identify studies published up to 31 March 2022. The PRISMA guidelines were used for reporting. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were obtained using fixed-effects models.

RESULTS

Twenty-six studies of 6870 patients with T2DM and 11,879 controls were identified. Compared with the other ABO groups, people with blood type B were at higher risk of T2DM (OR: 1.30, 95% CI: 1.20-1.41), while group O was associated with a lower risk (OR: 0.92, 95% CI: 0.86-0.98). There were no significant associations of T2DM with blood types A or AB, or Rh factor.

CONCLUSION

Individuals with blood type B are at higher risk of developing T2DM. Therefore, they should be screened for T2DM on a frequent basis and be made aware of the importance of maintaining a balanced diet and regular exercise for the prevention of obesity and T2DM.

PROSPERO REGISTRATION NUMBER

CRD42022353945.

The Roles of Gut Microbiome and Plasma Metabolites in the Associations between ABO Blood Groups and Insulin Homeostasis: The Microbiome and Insulin Longitudinal Evaluation Study (MILES)

Non-O blood groups are associated with decreased insulin sensitivity and risk of type 2 diabetes. A recent study pinpointed the associations between ABO blood groups and gut microbiome, which may serve as potential mediators for the observed increased disease risks. We aimed to characterize associations between ABO haplotypes and insulin-related traits as well as potential mediating pathways. We assessed insulin homeostasis in African Americans (AAs; n = 109) and non-Hispanic whites (n = 210) from the Microbiome and Insulin Longitudinal Evaluation Study. The ABO haplotype was determined by six SNPs located in the ABO gene. Based on prior knowledge, we included 21 gut bacteria and 13 plasma metabolites for mediation analysis. In the white study cohort (60 ± 9 years, 42% male), compared to the O1 haplotype, A1 was associated with a higher Matsuda insulin sensitivity index, while a lower relative abundance of Bacteroides massiliensis and lactate levels. Lactate was a likely mediator of this association but not Bacteroides massiliensis. In the AAs group (57 ± 8 years, 33% male), we found no association between any haplotype and insulin-related traits. In conclusion, the A1 haplotype may promote healthy insulin sensitivity in non-Hispanic whites and lactate likely play a role in this process but not selected gut bacteria.

The correlation between non-O blood group type and recurrent catheter-associated urinary tract infections in critically ill patients: A retrospective study

Objective

To investigate the correlation between the ABO blood group and the risk of recurrent catheter-associated urinary tract infections (CA-UTI) and multi-drug resistant (MDR) organism reinfection in the critically ill.

Methods

This retrospective cohort study enrolled adult patients admitted to the intensive care unit (ICU) with confirmed CA-UTI to investigate the correlation between ABO type and the susceptibility to recurrent, reinfection and MDR reinfection. Patients were classified into two groups based on ABO type (O blood group versus non-O blood group).

Results

A total of 81 patients were included in the study: 37 in the O blood group and 44 in the non-O blood group. Patients in the O blood group were associated with significantly lower odds of recurrent CA-UTI (adjusted odds ratio 0.28; 95% confidence interval 0.08, 0.95), a shorter ICU length of stay (LOS) (estimate [SE] –0.24 [0.05]), hospital LOS (estimate [SE] –0.15 [0.03]) and mechanical ventilation duration (estimate [SE] –0.41 [0.07]) compared with the non-O blood group type.

Conclusion

Non-O blood group type might be a risk factor for recurrent CA-UTI and infection with MDR organism.

B-Cell Lymphoma Producing IgM Anti-B Antibody: A Case Report

ABO blood group system is the most important blood group system in transfusion and transplantation medicine. Diffuse large B-cell lymphoma (DLBCL) is the most common type of non-Hodgkin lymphomas (NHLs) worldwide. There have been some studies that lymphoma could affect ABO blood group system and thus affect blood transfusion strategy. However, the mechanisms lymphoma affecting ABO blood group system have not been fully elucidated so far. Here, we report a case of a patient who was a 72-year-old Chinese man came to our hospital for medical advice because of cervical lymphadenophathy. The patient was subsequently diagnosed with diffuse large B-cell lymphoma by lymph-node biopsy. His ABO blood group was initially typed as B on November 7, 2020. He was transfusing B type leukocyte poor RBCs (LPR) before we found the patient’s ABO blood group discrepancy on December 2, 2020 by forward and reverse typing methods, which the discrepancy was verified by genotyping. The patient began to transfuse O type washed RBCs (WRBC) since then. Compared to transfuse B type leukocyte poor RBCs (LPR), the efficiency of transfusing O type washed RBCs (WRBC) was better. Although hemoglobin level did not greatly improve, indirect bilirubin level evidently decreased. Furthermore, we found B-cell lymphoma affected blood transfusion strategy by producing IgM anti-B antibody in this case. Clinicians should need to be aware of the effect of B-cell lymphoma on blood transfusion strategy.

A genome-wide association study in a large community-based cohort identifies multiple loci associated with susceptibility to bacterial and viral infections

There is limited data on host-specific genetic determinants of susceptibility to bacterial and viral infections. Genome-wide association studies using large population cohorts can be a first step towards identifying patients prone to infectious diseases and targets for new therapies. Genetic variants associated with clinically relevant entities of bacterial and viral infections (e.g., abdominal infections, respiratory infections, and sepsis) in 337,484 participants of the UK Biobank cohort were explored by genome-wide association analyses. Cases (n = 81,179) were identified based on ICD-10 diagnosis codes of hospital inpatient and death registries. Functional annotation was performed using gene expression (eQTL) data. Fifty-seven unique genome-wide significant loci were found, many of which are novel in the context of infectious diseases. Some of the detected genetic variants were previously reported associated with infectious, inflammatory, autoimmune, and malignant diseases or key components of the immune system (e.g., white blood cells, cytokines). Fine mapping of the HLA region revealed significant associations with HLA-DQA1, HLA-DRB1, and HLA-DRB4 locus alleles. PPP1R14A showed strong colocalization with abdominal infections and gene expression in sigmoid and transverse colon, suggesting causality. Shared significant loci across infections and non-infectious phenotypes in the UK Biobank cohort were found, suggesting associations for example between SNPs identified for abdominal infections and CRP, rheumatoid arthritis, and diabetes mellitus. We report multiple loci associated with bacterial and viral infections. A better understanding of the genetic determinants of bacterial and viral infections can be useful to identify patients at risk and in the development of new drugs.

Variation in COVID-19 Disease Severity and Clinical Outcomes Between Different ABO Blood Groups

The primary objective of this study was to explore whether coronavirus disease 2019 (COVID-19) severity and outcomes varied between different ABO blood groups. This retrospective study included 363 COVID-19 confirmed patients who had their blood group recorded in the hospital medical records, from March to June 2020. Data representing demographics, clinical features, vital signs, laboratory findings, and COVID-19 outcomes were collected. Multivariate logistic regression was used for analysis and the results were adjusted for sociodemographic, clinical, and laboratory variables. The patients' mean age was 50 ± 17.8 years. Of the 363 patients, 30% were blood group A, 22.3% were blood group B, 8.8% were blood group AB, and 38.8% were blood group O. Bivariate analysis showed that patients with blood group AB were more likely to be free of any medical disease (65.6%) compared to other blood groups (p = 0.007). Fever was the most common presenting complaint (66.7%), and it did not significantly vary with changes in ABO blood groups (p = 0.230). Regarding laboratory characteristics, only C-reactive protein (CRP) levels were significantly associated with the blood groups, with high levels seen in blood groups A, B, and O (p = 0.036). In multivariate analysis, variations in emergency department (ED) disposition, requirement of intensive care unit care, and requirement of mechanical ventilation were not statistically significant among the different ABO blood groups. Furthermore, no correlation was found between hospital death and the different ABO blood groups. In conclusion, COVID-19 is most prevalent among patients with blood group O and least prevalent among those with blood group AB. No particular blood group had worse COVID-19 disease severity and outcomes than other blood groups. Therefore, we believe that ABO blood grouping should not be used as a major assessment tool for COVID-19 disease severity and outcome, and other known risk factors should be investigated.

Clinical Impact of the ABO Blood Type in Patients with Rheumatic Diseases: Is there a Link to the ABO and Rhesus?

Objectives

Several studies have shown associations of ABO and Rh blood groups with various diseases; however, the relationship of ABO and Rh blood groups with rheumatic diseases are scarce. The aim of the present study was to examine whether there is an association between ABO and Rh blood groups and the types of rheumatic diseases.

Method

In this multi-centre cross-sectional study, sociodemographic data, type of rheumatic disease, and type ABO and Rh blood groups were examined for patients with different rheumatic diseases.

Results

A total of 304 patients; 207 (68.1%) were diagnosed with rheumatoid arthritis, and 40 (13.2%) had systemic lupus erythematosus. The patients were assessed for blood types; 37.8% patients had A type, 27.6% had B type, 19.1% had O type, and 15.4% had AB type. The Rh (+) blood group was more prevalent (89.1%) than Rh (-). Blood group A was more prevalent in patients with rheumatic disease, followed by B, O, and AB respectively, although there was no significant difference in the distribution of ABO groups among rheumatic diseases. Female gender, smoking, and anti-cyclic citrullinated peptide are significantly different between the blood groups within rheumatic diseases.

Conclusion

The A and Rh (+) blood groups were more commonly observed in patients with rheumatic diseases. There was lack of association between types of rheumatic diseases and ABO blood groups. The study provides knowledge for the interaction between ABO blood groups and several risk factors related to rheumatic diseases and may serve a guide for future clinical studies.

ABO blood group and skin cancers

Beside the role of ABO group in immunohaematology, there is accumulating evidence that the ABO blood group also plays a key role in various human disorders. The interest in blood groups and their association with disease stems from the awareness that blood group antigens are incredibly important components in the process of cell maturation and control. Studies have indicated a link between cancer and the ABO blood group. The appearance or disappearance of blood type antigens is now considered a hallmark of malignancy in many common cancers. Several tumour markers are in fact known blood group antigens. The aim of this review is to describe the history and possible functions of the ABO group and then summarize the association between blood groups and skin cancers.

Association between ABO blood groups and rhesus antigen and susceptibility to COVID-19 in the Yazd hospital

Blood group antigens are one of the most important antigens in humans that have an impact on susceptibility to disease and may be used as a prognosis factor in different diseases such as COVID-19. The study aimed to investigate the relationship between ABO blood groups and Rhesus antigen and susceptibility to COVID-19. The clinical data of 398 subjects were used in the investigation collected from 148 cases vs. 250 controls. This information was obtained from Shahid Sadoughi Hospital of Yazd (IRAN) University. Blood groups and outcomes were assessed using statistical tests for four populations: COV + vs. COV− and COV +/deceased vs. COV +/live. Out of a total of 148 COVID-19 patients, 80 (54/1%) were male, 68 (45/9%) were female. Among these patients, 33 (22/6%) had type A+, 44 (30/1%) had type B+, 13 (8/9%) had type AB+, and 36 (24/7%) had type O+. On the other hand, out of 148 patients, 126 (86/3%) had positive blood types, and 20 (13/7%) had negative blood types. As a result, no significant difference was found in the relationship between ABO blood groups and RH type and susceptibility to COVID-19 (p-value = 0.392 and p-value = 0.847, respectively). Other data showed a significant difference between patients group with other parameters such as age (p-value<0.001) and gender (p-value<0.001). Although in this study there was no association between blood type and RH type with COVID-19, findings of the association between age and gender can confirm the results of previous studies.

The Relation of ABO Blood Group to the Severity of Coronavirus Disease: A Cross-Sectional Study From a Tertiary Care Hospital in Karachi

Background

Blood groups are considered to have an impact on the occurrence and severity of coronavirus disease. While among Chinese and Caucasian, blood group O individuals were less and group A were more likely to have severe disease and mortality, data on South Asians aren’t available. 

Objective

This study aimed to find out the association of disease severity with blood group among coronavirus disease 2019 (COVID-19) patients.

Materials and methodology

Data were collected on a predesigned questionnaire containing details of patient demographics, medical comorbidities, clinical presentation, and laboratory parameters. Multiple logistic regression was used to determine the association of the blood group with the severity of coronavirus disease.

Result

Among the study participants, blood group B has the highest distribution (39.8%), followed by O (30.0), A (21.9%), and AB (8.1%). About three-fourths (69.9%) had mild to moderate disease while 30.0% had severe disease. Age, gender, hypertension, diabetes mellitus, and hemoglobin level were all associated with disease severity among COVID-19 patients in univariate analysis on P-value for selection (<0.25). The final model showed that the odds of disease severity is 3.62 times higher among males (OR: 3.62, 95% CI: 2.15-6.08) and 2.00 times higher among diabetic patients (OR: 2.00, 95% CI: 1.10-3.01) as compared to female and non-diabetic respectively. However, there was no significant association found between blood group and disease severity.

Conclusion

Blood groups don’t have any role in forecasting the severity of coronavirus disease. However, the male gender and diabetics are prone to have severe disease.

Major Insights in Dynamics of Host Response to SARS-CoV-2: Impacts and Challenges

The coronavirus disease 2019 (COVID-19), a pandemic declared by the World Health Organization on March 11, 2020, is caused by the infection of highly transmissible species of a novel coronavirus called severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2). As of July 25, 2021, there are 194,372,584 cases and 4,167,937 deaths with high variability in clinical manifestations, disease burden, and post-disease complications among different people around the globe. Overall, COVID-19 is manifested as mild to moderate in almost 90% of the cases and only the rest 10% of the cases need hospitalization. However, patients with older age and those having different comorbidities have made worst the pandemic scenario. The variability of pathological consequences and clinical manifestations of COVID-19 is associated with differential host-SARS-CoV-2 interactions, which are influenced by the factors that originated from the SARS-CoV-2 and the host. These factors usually include the genomic attributes and virulent factors of the SARS-CoV-2, the burden of coinfection with other viruses and bacteria, age and gender of the individuals, different comorbidities, immune suppressions/deficiency, genotypes of major histocompatibility complex, and blood group antigens and antibodies. We herein retrieved and reviewed literatures from PubMed, Scopus, and Google relevant to clinical complications and pathogenesis of COVID-19 among people of different age, sex, and geographical locations; genomic characteristics of SARS-CoV-2 including its variants, host response under different variables, and comorbidities to summarize the dynamics of the host response to SARS-CoV-2 infection; and host response toward approved vaccines and treatment strategies against COVID-19. After reviewing a large number of published articles covering different aspects of host response to SARS-CoV-2, it is clear that one aspect from one region is not working with the scenario same to others, as studies have been done separately with a very small number of cases from a particular area/region of a country. Importantly, to combat such a pandemic as COVID-19, a conclusive understanding of the disease dynamics is required. This review emphasizes on the identification of the factors influencing the dynamics of host responses to SARS-CoV-2 and offers a future perspective to explore the molecular insights of COVID-19.

The association of ABO blood groups and trauma outcomes: A retrospective analysis of 3779 patients

Background:

There is currently a lack of understanding regarding the link between ABO blood types with outcomes of traumatically injured patients. The purpose of this study was to determine the association of ABO blood types with outcomes in traumatically injured patients separated by injury type.

Methods:

This retrospective study evaluated trauma patients at an urban, Level 1 trauma center from January 1, 2017, through December 31, 2017. Patients were excluded if they were pregnant or <16 years old. Recorded outcomes included: ABO blood group, mortality, Injury Severity Score (ISS), race, injury type, mechanism of injury, and complications. Data analysis was performed using descriptive statistics including Chi-squared, Kruskal–Wallis, and F-test calculations.

Results:

A total of 3779 patients were included in this study. No significant differences were present in mean age or ISS between blood types. In patients with penetrating injuries, blood type O was associated with a significant increase in mortality (P = 0.017), red blood cell transfusion (P = 0.027), and massive transfusion protocol (MTP) (P = 0.026) compared to non-O blood types. In patients with blunt injuries, blood type AB was associated with a significant increase in mortality rate compared to non-AB blood types (P = 0.03).

Conclusion:

ABO blood type is connected with an underlying process which affects trauma outcomes, including mortality. Blood type O is associated with increased blood transfusion, MTP, and mortality during the initial hospitalization following a traumatic penetrating injury, while blood type AB is associated with increased mortality during the initial hospitalization following a blunt traumatic injury.

The Association Between ABO Blood Group and Preeclampsia: A Systematic Review and Meta-Analysis

Objective: This meta-analysis comprehensively evaluated the association between ABO blood group and the risk of preeclampsia (PE).

Design: Systematic review and meta-analysis.

Data sources: PubMed, Web of Science, and ScienceDirect databases from their inception to September 23, 2020.

Methods: Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were obtained through random-effects and fixed-effects models according to heterogeneity. Meta-regression analysis was applied to explore the source of heterogeneity. We conducted a subgroup analysis by the publication year, study design, state, and Newcastle-Ottawa Scale (NOS) score. In addition, we calculated the rate of each ABO blood group in PE by total pooled effects.

Results: A total of 12 articles with 714,153 patients were included in our analysis. Compared with people without PE (control group), the O blood group presented a lower risk of PE (OR 0.95, 95% CI 0.93–0.97). The AB (OR 1.46, 95% CI 1.12–1.91) blood group presented a higher risk. However, the total pooled OR and 95% CI for the A (OR 1.02, 95% CI 0.90–1.16) and B (OR 1.02, 95% CI 0.98–1.05) blood groups were not significant. The funnel plot and linear regression equation showed that there was no publication bias for the O, A, or B blood groups (all P > 0.05). However, the funnel plot and linear regression equation for the AB blood group were obviously asymmetric (P < 0.05), and the publication bias persisted even after the trim-and-fill method was applied (P < 0.05). Multivariable meta-regression analysis did not find a specific source of heterogeneity. The A blood group showed an association with early-onset PE (OR 0.53, 95% CI 0.33–0.83), and the other blood groups showed no significant differences. In PE, the rates of the O, A, B, and AB blood groups decreased gradually (0.39, 0.33, 0.19, 0.07).

Conclusion: These findings suggest that pregnant women with AB blood group are more likely to develop PE, and more attention should be paid to AB blood group whose blood pressure is high but not sufficient to diagnose PE.

Systematic Review Registration: Prospero CRD42021227930.

ABO phenotype and SARS-CoV-2 infection: Is there any correlation?

COVID-19 is the currently evolving viral disease worldwide. It mainly targets the respiratory organs, tissues and causes illness. A plethora of studies has been performing to bring proper treatment and prevent people from the infection. Likewise, susceptibility to some infectious diseases has been associated with blood group phenotypes. The co-relationship of blood group with the occurrence of SARS-CoV-2 infection and death has been examined in numerous studies. This review explained the described studies regarding the correlation of blood group and the other essential factors with COVID-19.

ABO blood group and COVID-19: an updated systematic literature review and meta-analysis

BACKGROUND

Following the first reports in the literature, the association between the ABO blood group and SARS-CoV-2 infection has been investigated by a number of studies, although with varying results. The main object of this systematic review was to assess the relationship between the ABO blood group and the occurrence and severity of COVID-19.

MATERIALS AND METHODS

A systematic literature search using appropriate MeSH terms was performed through Medline and PubMed. The outcomes considered were the prevalence of the blood group O vs non-O types in SARS-CoV-2 infected and non-infected subjects, and the severity of SARS-CoV-2 infection according to ABO group. The methodological quality of the studies included in the analysis was assessed with the Newcastle-Ottawa Scale, and the overall quality of the available evidence using the GRADE system. Benchmarks used to evaluate the effect size were odd ratios (ORs) for case control studies and risk ratios (RRs) for cohort studies.

RESULTS

Twenty-one studies were included in the analysis. Overall, individuals with group O had a lower infection rate compared to individuals of non-O group (OR: 0.81; 95% CI: 0.75, 0.86). However, the difference in the effect size was significantly lower in cohort studies compared to case control studies. No evidence was found indicating an effect of the O type on the disease severity in the infected patients.

DISCUSSION

We have found low/very low evidence that group O individuals are less susceptible to SARS-CoV-2 infection compared to those in the non-O group. No evidence was found indicating an effect of the O type on disease severity in SARS-CoV-2 infection.

The Probable Association between Blood Groups and Prognosis of COVID-19

BACKGROUND

We aimed to verify the association between blood group systems and prognosis of SARS-Cov-2 disease.

METHODS

In this cross-sectional study, 329 patients infected with SARS-Cov-2 diagnosed based on their COVID-19 RT-PCR results and chest CT scans, were enrolled in the study. These patients were admitted to Kamkar Arab Nia Hospital, Qom, Iran from March to June 2020. Their blood groups and RH were determined, and demographic characteristics and clinical signs of patients were recorded. The patients' temperature and peripheral capillary oxygen saturation levels (SpO2) were measured. Finally, the duration of hospitalization, intubation, and death rate were also analyzed.

RESULTS

The results of the patients' blood group analysis were as follows: 129(39.2%) patients had A type, 66(20.1%) B type, 21(6.4%) AB type, and 113(34.3%) O type. Of 329 patients, 297 (90.3%) had Rh antigen. The dead cases were higher in O blood type at 13 cases (11.5%). Considering the positive and negative rhesus antigen, 31 (10.4%) and 1 (3.1%) were dead respectively, but the difference was not statically significant. As for the A group, the mean of admission duration (8.4±6.1 days) was not significantly different from the B group (8.8 ±7.2 days). AB group with a mean (7.4 ±4.4 days) was not significantly different from the O group (7.8 ± 5.4 days). There was no significant difference in the duration of hospitalization in RH patients, positive or negative. B blood group showed a significant association with the time interval to return to normal oxygen levels.

CONCLUSION

Blood type was not associated with COVID-19 death rate, nor was it associated with admission duration. B blood group showed a significant association with the time interval to return to normal oxygen levels.

Comprehensive Glycomic Approach Reveals Novel Low-Molecular-Weight Blood Group-Specific Glycans in Serum and Cerebrospinal Fluid

ABO blood antigens on the human red blood cell membrane as well as different cells in various human tissues have been thoroughly studied. Anti-A and -B antibodies of IgM are present in serum/plasma, but blood group-specific glyco-antigens have not been extensively described. In this study, we performed comprehensive and quantitative serum glycomic analyses of various glycoconjugates and free oligosaccharides in all blood groups. Our comprehensive glycomic approach revealed that blood group-specific antigens in serum/plasma are predominantly present on glycosphingolipids on lipoproteins rather than glycoproteins. Expression of the ABO antigens on glycosphingolipids depends not only on blood type but also on secretor status. Blood group-specific glycans in serum/plasma were classified as type I, whereas those on RBCs had different structures including hexose and hexosamine residues. Analysis of free oligosaccharides revealed that low-molecular-weight blood group-specific glycans, commonly containing lacto-N-difucotetraose, were expressed in serum/plasma according to blood group. Furthermore, comprehensive glycomic analysis in human cerebrospinal fluid showed that many kinds of free oligosaccharides were highly expressed, and low-molecular-weight blood group-specific glycans, which existed in plasma from the same individuals, were present. Our findings provide the first evidence for low-molecular-weight blood group-specific glycans in both serum/plasma and cerebrospinal fluid.

The Role of Immunogenetics in COVID-19

Coronavirus disease 2019 (COVID-19) is induced by SARS-CoV-2 and may arise as a variety of clinical manifestations, ranging from an asymptomatic condition to a life-threatening disease associated with cytokine storm, multiorgan and respiratory failure. The molecular mechanism behind such variability is still under investigation. Several pieces of experimental evidence suggest that genetic variants influencing the onset, maintenance and resolution of the immune response may be fundamental in predicting the evolution of the disease. The identification of genetic variants behind immune system reactivity and function in COVID-19 may help in the elaboration of personalized therapeutic strategies. In the frenetic look for universally shared treatment plans, those genetic variants that are common to other diseases/models may also help in addressing future research in terms of drug repurposing. In this paper, we discuss the most recent updates about the role of immunogenetics in determining the susceptibility to and the history of SARS-CoV-2 infection. We propose a narrative review of available data, speculating about lessons that we have learnt from other viral infections and immunosenescence, and discussing what kind of aspects of research should be deepened in order to improve our knowledge of how host genetic variability impacts the outcome for COVID-19 patients.

ABO blood group and COVID-19: a review on behalf of the ISBT COVID-19 working group

Growing evidence suggests that ABO blood group may play a role in the immunopathogenesis of SARS-CoV-2 infection, with group O individuals less likely to test positive and group A conferring a higher susceptibility to infection and propensity to severe disease. The level of evidence supporting an association between ABO type and SARS-CoV-2/COVID-19 ranges from small observational studies, to genome-wide-association-analyses and country-level meta-regression analyses. ABO blood group antigens are oligosaccharides expressed on red cells and other tissues (notably endothelium). There are several hypotheses to explain the differences in SARS-CoV-2 infection by ABO type. For example, anti-A and/or anti-B antibodies (e.g. present in group O individuals) could bind to corresponding antigens on the viral envelope and contribute to viral neutralization, thereby preventing target cell infection. The SARS-CoV-2 virus and SARS-CoV spike (S) proteins may be bound by anti-A isoagglutinins (e.g. present in group O and group B individuals), which may block interactions between virus and angiotensin-converting-enzyme-2-receptor, thereby preventing entry into lung epithelial cells. ABO type-associated variations in angiotensin-converting enzyme-1 activity and levels of von Willebrand factor (VWF) and factor VIII could also influence adverse outcomes, notably in group A individuals who express high VWF levels. In conclusion, group O may be associated with a lower risk of SARS-CoV-2 infection and group A may be associated with a higher risk of SARS-CoV-2 infection along with severe disease. However, prospective and mechanistic studies are needed to verify several of the proposed associations. Based on the strength of available studies, there are insufficient data for guiding policy in this regard.

Histone deacetylase inhibitors suppress ACE2 and ABO simultaneously, suggesting a preventive potential against COVID-19

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has spread worldwide as a pandemic throughout 2020. Since the virus uses angiotensin-converting enzyme 2 (ACE2) as a receptor for cellular entry, increment of ACE2 would lead to an increased risk of SARS-CoV-2 infection. At the same time, an association of the ABO blood group system with COVID-19 has also been highlighted: there is increasing evidence to suggest that non-O individuals are at higher risk of severe COVID-19 than O individuals. These findings imply that simultaneous suppression of ACE2 and ABO would be a promising approach for prevention or treatment of COVID-19. Notably, we have previously clarified that histone deacetylase inhibitors (HDACIs) are able to suppress ABO expression in vitro. Against this background, we further evaluated the effect of HDACIs on cultured epithelial cell lines, and found that HDACIs suppress both ACE2 and ABO expression simultaneously. Furthermore, the amount of ACE2 protein was shown to be decreased by one of the clinically-used HDACIs, panobinostat, which has been reported to reduce B-antigens on cell surfaces. On the basis of these findings, we conclude that panobinostat could have the potential to serve as a preventive drug against COVID-19.

The Lebanese COVID-19 Cohort; A Challenge for the ABO Blood Group System

A sudden outbreak of pneumonia caused by the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) has rapidly spread all over the world facilitating the declaration of the resultant disease as a pandemic on March 2020. Predisposing factors for acquiring COVID-19 and for developing a severe form of this disease were postulated to be related to the epidemiological, clinical, and genetic characteristics of the patients. Biological markers such as the ABO blood group system were amongst these factors that were proposed to be linked to the variability in the disease course and/or the prevalence of the infection among different groups. Herein, we conducted the first retrospective case-control study from the Middle East and North Africa that tackles the association between the blood group types and the susceptibility to, as well as the severity of, SARS-CoV-2 infection. Contrary to the most acknowledged hypothesis, our results challenged the significance of this association and questioned the role of the ABO blood group system in dictating the severity of this disease. For future similar studies, we endorsed analyzing larger cohorts among different populations and we encouraged implementing more rigorous approaches to diminish the potential confounding effect of some underlying comorbidities and genetic variants that are known to be associated with the ABO blood group system.

Association of ABO and Rh Blood Group Phenotypes with Type 2 Diabetes Mellitus at Felege Hiwot Comprehensive Referral Hospital Bahir Dar, Northwest Ethiopia

BACKGROUND

ABO and Rh blood group antigens are thought to be among genetic determinants of type 2 diabetes mellitus. Identification of blood group phenotypes are more associated with type 2 diabetes mellitus. It will be helpful for individuals who are susceptible blood groups to take care of themselves by avoiding other predisposing factors and taking preventive measures.

METHODS

Hospital-based comparative cross-sectional study was carried out from February to April 2019 at Felege Hiwot Comprehensive Referral Hospital. Sociodemographic and clinical data were collected with a semistructured pretested questionnaire. ABO and Rh Blood group were determined by slide and test tube methods. Biochemical parameters were determined with Mindray BS-200E fully automated clinical chemistry analyzer. Data were analyzed by IBM SPSS version 20 statistical software. Chi-square test and logistic regression analysis were employed for data analysis. A P value of < 0.05 was considered statistically significant.

RESULTS

From a total of 424 participants included for this study, blood group O was found higher in frequency with 74 (34.9%) and 97 (45.75%) for cases and healthy controls, respectively. ABO blood groups showed significant association with T2DM, a chi-square value of 12.163 and P value of 0.007. However, the Rh blood group was not associated with T2DM. Binary logistic regression analysis revealed that blood group B had a higher risk (OR: 2.12, 95% CI: 1.33-3.32) and blood group O had decreased risk (OR: 0.636, 95% CI: 0.43-0.94) of T2DM as compared to other blood groups.

CONCLUSION

ABO blood group antigens showed significant association with type 2 diabetes mellitus. Blood group B was associated with an increased risk and O blood group with decreased risk of type 2 diabetes mellitus.

Individuals with a Rh-positive but not Rh-negative blood group are more vulnerable to SARS-CoV-2 infection: demographics and trend study on COVID-19 cases in Sudan

Coronavirus disease 2019 (COVID-19) is an infectious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In Sudan, several haematological studies were conducted to study the ABO blood group distribution among the population, in which the O blood group was dominant followed by the A blood group. However, there is no systematic study into any correlation between COVID-19 and the population's blood group types, therefore we have intended to study the possible effect of blood group on the acquisition of SARS-CoV-2 infection. A questionnaire-based case-control study was carried out on 557 individuals with COVID-19 in Sudan; factors such as age, blood group, previous malaria infection, history of ailments such as diabetes, hypertension and symptoms suffered were also considered and analysed. More women were infected than men, and individuals between 25 and 35 years were the most affected age group. O Rhesus-positive (O+) blood group was the least affected by the disease while A Rhesus-positive (A+) individuals were the most vulnerable. Fatigue, fever and loss of smell were the major symptoms among the patients, but 13% of SARS-COV-2-positive individuals remained asymptomatic. As the Sudan population is largely constituted of O Rhesus-positive inhabitants (approximately 50%) these results might explain the relatively lower COVID-19 incidence in the country.

Blood type and outcomes in patients with COVID-19

This study aimed to determine if there is an association between ABO blood type and severity of COVID-19 defined by intubation or death as well as ascertain if there is variability in testing positive for COVID-19 between blood types. In a multi-institutional study, all adult patients who tested positive for COVID-19 across five hospitals were identified and included from March 6th to April 16th, 2020. Hospitalization, intubation, and death were evaluated for association with blood type. Univariate analysis was conducted using standard techniques and logistic regression was used to determine the independent effect of blood type on intubation and/or death and positive testing. During the study period, there were 7648 patients who received COVID-19 testing throughout the institutions. Of these, 1289 tested positive with a known blood type. A total of 484 (37.5%) were admitted to hospital, 123 (9.5%) were admitted to the ICU, 108 (8.4%) were intubated, 3 (0.2%) required ECMO, and 89 (6.9%) died. Of the 1289 patients who tested positive, 440 (34.2%) were blood type A, 201 (15.6%) were blood type B, 61 (4.7%) were blood type AB, and 587 (45.5%) were blood type O. On univariate analysis, there was no association between blood type and any of the peak inflammatory markers (peak WBC, p = 0.25; peak LDH, p = 0.40; peak ESR, p = 0.16; peak CRP, p = 0.14) nor between blood type and any of the clinical outcomes of severity (admission p = 0.20, ICU admission p = 0.94, intubation p = 0.93, proning while intubated p = 0.58, ECMO p = 0.09, and death p = 0.49). After multivariable analysis, blood type was not independently associated with risk of intubation or death (referent blood type A; blood type B: AOR: 0.72, 95% CI: 0.42-1.26, blood type AB: AOR: 0.78, CI: 0.33-1.87, blood type O: AOR: 0.77, CI: 0.51-1.16), rhesus factor positive (Rh+): AOR: 1.03, CI: 0.93-1.86. Blood type A had no correlation with positive testing (AOR: 1.00, CI: 0.88-1.13), blood type B was associated with higher odds of testing positive for disease (AOR: 1.28, CI: 1.08-1.52), AB was also associated with higher odds of testing positive (AOR: 1.37, CI: 1.02-1.83), and O was associated with a lower risk of testing positive (AOR: 0.84, CI: 0.75-0.95). Rh+ status was associated with higher odds of testing positive (AOR: 1.23, CI: 1.003-1.50). Blood type was not associated with risk of intubation or death in patients with COVID-19. Patients with blood types B and AB who received a test were more likely to test positive and blood type O was less likely to test positive. Rh+ patients were more likely to test positive.

Hypercoagulopathy and Adipose Tissue Exacerbated Inflammation May Explain Higher Mortality in COVID-19 Patients With Obesity

COVID-19, caused by SARS-CoV-2, is characterized by pneumonia, lymphopenia, exhausted lymphocytes and a cytokine storm. Several reports from around the world have identified obesity and severe obesity as one of the strongest risk factors for COVID-19 hospitalization and mechanical ventilation. Moreover, countries with greater obesity prevalence have a higher morbidity and mortality risk of developing serious outcomes from COVID-19. The understanding of how this increased susceptibility of the people with obesity to develop severe forms of the SARS-CoV-2 infection occurs is crucial for implementing appropriate public health and therapeutic strategies to avoid COVID-19 severe symptoms and complications in people living with obesity. We hypothesize here that increased ACE2 expression in adipose tissue displayed by people with obesity may increase SARS-CoV-2 infection and accessibility to this tissue. Individuals with obesity have increased white adipose tissue, which may act as a reservoir for a more extensive viral spread with increased shedding, immune activation and pro-inflammatory cytokine amplification. Here we discuss how obesity is related to a pro-inflammatory and metabolic dysregulation, increased SARS-CoV-2 host cell entry in adipose tissue and induction of hypercoagulopathy, leading people with obesity to develop severe forms of COVID-19 and also death. Taken together, it may be crucial to better explore the role of visceral adipose tissue in the inflammatory response to SARS-CoV-2 infection and investigate the potential therapeutic effect of using specific target anti-inflammatories (canakinumab or anakinra for IL-1β inhibition; anti-IL-6 antibodies for IL-6 inhibition), anticoagulant or anti-diabetic drugs in COVID-19 treatment of people with obesity. Defining the immunopathological changes in COVID-19 patients with obesity can provide prominent targets for drug discovery and clinical management improvement.

ABO blood group relationships to kidney transplant recipient and graft outcomes

Introduction

Certain ABO blood types have been linked to cardiovascular disease, infection and cancers. The effect of recipient ABO blood group on patient and graft survival has not been studied in ABO-matched kidney transplantation. This study aims to determine the association between kidney transplant recipient ABO blood groups with patient and graft survival in Australian and New Zealand.

Methods

All Australian and New Zealand transplant recipients who received ABO-compatible primary kidney transplants between 1995–2016 were analysed using a de-identified dataset from the Australia and New Zealand Dialysis and Transplant (ANZDATA) Registry. Primary analysis was undertaken of recipient ABO blood group O versus non-O blood groups. The primary outcome was patient survival post kidney transplantation and the secondary outcome was death censored graft survival. Recipient age at first transplant, gender, ethnicity, body mass index, smoking status, vascular disease, presence of diabetes mellitus, chronic lung disease, primary kidney disease, donor source, donor age and gender, and era of transplants were included in the multivariate model as confounders.

Results and conclusions

On analysis of 15,523 kidney transplant recipients, blood group O was not associated with patient survival (hazard ratio (HR) 0.96, 95% confidence interval (CI) 0.89–1.04) nor death censored graft survival (HR 0.97, 95% CI 0.89–1.05) compared to non-blood group O recipients. Competing risks analyses showed an increased risk of cancer-related mortality in blood group O recipients on univariate analyses (HR 1.18, 95% CI 1.01–1.37) however, this became insignificant on multivariate analyses. On secondary analyses, recipient blood group AB (4.11% participants) was associated with inferior death censored graft survival compared to those with blood group O (HR 1.24, 95% CI 1.02–1.50). Although recipient ABO blood groups were not associated with patient nor graft survival, differences in cause-specific mortality between individual blood groups cannot be excluded based on current analyses.

Association Between ABO Blood Group System and COVID-19 Susceptibility in Wuhan

Background: The ABO blood group system has been associated with multiple infectious diseases, including hepatitis B, dengue haemorrhagic fever and so on. Coronavirus disease 2019 (COVID-19) is a new respiratory infectious disease and the relationship between COVID-19 and ABO blood group system needs to be explored urgently.

Methods: A hospital-based case-control study was conducted at Zhongnan Hospital of Wuhan University from 1 January 2020 to 5 March 2020. A total of 105 COVID-19 cases and 103 controls were included. The blood group frequency was tested with the chi-square statistic, and odds ratios (ORs) with 95% confidence intervals (CIs) were calculated between cases and controls. In addition, according to gender, the studied population was divided into two subgroups, and we assessed the association between cases and controls by gender. Finally, considering lymphopenia as a feature of COVID-19, the relationship between the ABO blood group and the lymphocyte count was determined in case samples.

Results: The frequencies of blood types A, B, AB, and O were 42.8, 26.7, 8.57, and 21.9%, respectively, in the case group. Association analysis between the ABO blood group and COVID-19 indicated that there was a statistically significant difference for blood type A (P = 0.04, OR = 1.33, 95% CI = 1.02–1.73) but not for blood types B, AB or O (P = 0.48, OR = 0.90, 95% CI = 0.66–1.23; P = 0.61, OR = 0.88, 95% CI = 0.53–1.46; and P = 0.23, OR = 0.82, 95% CI = 0.58–1.15, respectively). An analysis stratified by gender revealed that the association was highly significant between blood type A in the female subgroup (P = 0.02, OR = 1.56, 95% CI = 1.08–2.27) but not in the male subgroup (P = 0.51, OR = 1.14, 95% CI = 0.78–1.67). The average level of lymphocyte count was the lowest with blood type A in patients, however, compared with other blood types, there was still no significant statistical difference.

Conclusions: Our findings provide epidemiological evidence that females with blood type A are susceptible to COVID-19. However, these research results need to be validated in future studies.

Evaluation of maternal rhesus blood type as a risk factor in adverse pregnancy outcomes in Korea: a nationwide health insurance database study

OBJECTIVES

The current study aimed to investigate whether pregnancy outcomes are affected by maternal rhesus (Rh) status by comparing the primigravida pregnancy outcomes of Rh-negative women with those of Rh-positive women.

METHODS

The study data were collected from the Korea National Health Insurance Claims Database and the National Health Screening Program for Infants and Children. In total, 1,664,882 primigravida women who gave birth between January 1, 2007 and December 31, 2014, were enrolled in this study. As the risk and severity of sensitization response increases with each subsequent pregnancy, only primigravida women were enrolled. The patients were divided into 2 groups according to Rh status, and the pregnancy outcomes were compared.

RESULTS

In total, 1,661,320 women in the Rh-positive group and 3,290 in the Rh-negative group were assessed. With regard to adverse pregnancy outcomes, there was no statistically significant difference between the 2 groups in terms of the prevalence of preeclampsia, postpartum hemorrhage, abruptio placenta, placenta previa, and uterine artery embolization. A univariate analysis revealed that none of the adverse pregnancy outcomes were significantly correlated to Rh status (preeclampsia: odds ratio [OR], 1.00, 95% confidence interval [CI], 0.81-1.23; postpartum hemorrhage: OR, 1.10, 95% CI, 0.98-1.24; abruptio placenta: OR, 0.80, 95% CI, 0.46-1.37; and placenta previa: OR, 1.08, 95% CI, 0.78-1.42). The adjusted ORs of postpartum hemorrhage and preterm birth did not significantly differ.

CONCLUSION

Maternal Rh status is not associated with adverse outcomes in primigravida women.

Relationship Between the Prevalence of Blood Groups and Severity of Leptospirosis: A Case-Control Study

Introduction:

The correlation between the prevalence and severity of leptospirosis with blood groups has not been investigated so far, but several studies have been conducted to link the infectious diseases with blood groups. The aim of this study was to investigate the prevalence of blood type in patients with leptospirosis and its association with disease severity.

Methods:

This is a case-control study performed on hospitalized patients with the diagnosis of leptospirosis in Mazandaran province, Iran, in 2018. The control group was selected from among the families of patients. Blood groups (ABO and Rh) and severity of the disease were assessed. Data were analyzed by SPSS 22.

Results:

A total of 300 people (150 in the case and 150 in the control) enrolled in the study. The mean age was 44.35 ± 15.39 years and 81.3% were men. The highest frequency of blood type in both groups was O+, A+, and B+, respectively. There was a statistically significant difference in the frequency of blood groups (P = .037). Comparison between severity of disease and blood types (ABO, Rh) showed no significant difference (P > .05).

Conclusions:

According to our study, O+ was the most common among patients with leptospirosis. The frequency of O in patients was significantly higher than in the control group, but there was no significant relationship between leptospirosis and Rh. The prevalence of this blood type was higher in people with a severe form of the disease. Finally, there is no statistically significant difference between the severity of the disease and ABO and Rh.

Correlation between an ABO Blood Group and Primary Femoral Head Necrosis: A Case-Control Study

Objective

To investigate the relationship between primary femoral head necrosis (ONFH) and an ABO blood group.

Methods

This study was a retrospective case–control trial. An analysis of the clinical data of an ABO blood group with 516 patients (case group) with ONFH and 489 limb‐fracture patients (control group) without previous hip pain was obtained from the Second Hospital of Shanxi Medical University from November 2015 to November 2018. The clinical data included gender, age, height, weight, a history of smoking, alcohol abuse, prior medical history, hormone use, and ABO blood type. A logistic regression model was used for univariate and multivariate analysis.

Results

From November 2015 to November 2018, there were 267 males and 249 females in the 516 cases of ONFH in the case group. The control group included 289 males and 200 females. In terms of age, the average age of the case group was significantly lower than that of the control group. In terms of body mass index (BMI), the BMI of the case group was significantly higher than that of the control group (P < 0.05). From the previous medical history of patients in the two groups (coronary heart disease, hypertension, cerebrovascular disease, diabetes, and peripheral vascular disease), there was no significant difference between the two groups from a statistical perspective (P < 0.05). However, according to the risk factors of ONFH (smoking, alcohol abuse, hyperlipidemia, and hormone‐use history), there were significant differences between the case group and the control group. There was no statistical difference in the quantitative distribution ratio of the four blood types – A, B, O, and AB – between the case group and the control group. The outcomes of logistic multiple regression analysis presented that there was no significant correlation between the occurrence of ONFH and blood type A, B, AB, and O (P > 0.05). However, there are significant differences in the disease progression between the different blood types. There was a significant difference in the progression of disease between type A and type O. Among them, patients with ONFH and type A blood had the fastest progression with an average of 2.318 years, and the slowest progression was found in type O blood with an average of 5.15 years.

Conclusions

The ABO blood group has no correlation with the occurrence of ONFH, but the ABO blood type is closely related to the disease progression of ONFH.

ABO Blood Groups, Rh Factor, and Thyroid Cancer Risk: To 'B' or Not to 'B'

Purpose: In this study, we aimed to evaluate ABO blood groups and Rh factor in patients with thyroid cancer.Methods: Demographical and clinical features, cytological results, ABO blood groups, and Rh factor status of patients with benign and malignant thyroid disease were evaluated. Histopathological features of thyroid cancer were compared in Rh positive and negative patients, and patients with different ABO blood groups.Results: Histopathological diagnosis was benign in 1,299 (63.5%) and malignant in 744 (36.5%) patients. There was no significant difference between benign and malignant patients in terms of age, sex, thyroid autoantibody positivity, and ABO blood groups (p > .05 for each). A significantly higher rate of patients with malignant disease were Rh positive compared to patients with benign disease (91.8% vs. 88.1%, p = .046). In thyroid cancer patients, extrathyroidal extension and advanced stage (3-4) were observed more frequently in patients with B compared to non-B blood groups (p = .028 and 0.042, respectively). The likelihood of the extrathyroidal extension was 4.272 (95%: 1.816-10.049) times higher in B blood group compared to non-B blood groups in patients with multifocal disease (p < .001). Patients with O blood group had lower rate of capsular invasion than patients with non-O blood groups (p = .018).Conclusion: Patients with B blood group had higher risk of extrathyroidal extension and advanced stage compared to patients with non-B blood group.

The Effect of Autophagic Activity on the Function of Apheresis Platelets and on the Efficacy of Clinical Platelet Transfusion

Platelet activation and survival jointly determine the efficacy of clinical platelet transfusion. This study aimed to discuss the effect of autophagic activity on activation and aggregation of apheresis platelets and on the efficacy of clinical platelet transfusion. In this study, we investigated the effects of autophagic activity of apheresis platelets for different blood types and after different storage durations on platelet activation and aggregation functions. By Western blot, immunofluorescence, and RT-qPCR detection, we found that with the prolongation of the storage duration, the expressions of both autophagy-related proteins and genes were upregulated in apheresis platelets and their expressions were insignificantly higher in the apheresis platelets of type A and O blood than in those of type B and type AB blood. After RAPA/IGF-1 pretreatment, there was a significant increase/reduction in autophagic activity. After RAPA and IGF-1 pretreatment, an opposite variation trend was observed with platelet activation and aggregation. Autophagic activity of platelets correlated negatively with the efficacy of clinical platelet transfusion. These research findings provide a theoretical basis for effective clinical platelet transfusion.

Pancreatic cancer risk is modulated by inflammatory potential of diet and ABO genotype: a consortia-based evaluation and replication study

Diets with high inflammatory potential are suspected to increase risk for pancreatic cancer (PC). Using pooled analyses, we examined whether this association applies to populations from different geographic regions and population subgroups with varying risks for PC, including variation in ABO blood type. Data from six case-control studies (cases, n = 2414; controls, n = 4528) in the Pancreatic Cancer Case-Control Consortium (PanC4) were analyzed, followed by replication in five nested case-control studies (cases, n = 1268; controls, n = 4215) from the Pancreatic Cancer Cohort Consortium (PanScan). Two polymorphisms in the ABO locus (rs505922 and rs8176746) were used to infer participants' blood types. Dietary questionnaire-derived nutrient/food intake was used to compute energy-adjusted dietary inflammatory index (E-DII®) scores to assess inflammatory potential of diet. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using multivariable-adjusted logistic regression. Higher E-DII scores, reflecting greater inflammatory potential of diet, were associated with increased PC risk in PanC4 [ORQ5 versus Q1=2.20, 95% confidence interval (CI) = 1.85-2.61, Ptrend < 0.0001; ORcontinuous = 1.20, 95% CI = 1.17-1.24], and PanScan (ORQ5 versus Q1 = 1.23, 95% CI = 0.92-1.66, Ptrend = 0.008; ORcontinuous = 1.09, 95% CI = 1.02-1.15). As expected, genotype-derived non-O blood type was associated with increased PC risk in both the PanC4 and PanScan studies. Stratified analyses of associations between E-DII quintiles and PC by genotype-derived ABO blood type did not show interaction by blood type (Pinteraction = 0.10 in PanC4 and Pinteraction=0.13 in PanScan). The results show that consuming a pro-inflammatory diet and carrying non-O blood type are each individually, but not interactively, associated with increased PC risk.

ABO blood group distributions in multiple sclerosis patients from Basque Country; O- as a protective factor

Background

The relation between ABO/Rh groups and multiple sclerosis (MS) has been proposed in several studies, however there is a controversy about the role of these groups in the disease. Although it has been reported that some groups can be protective or risk factors, there is no consensus and discordant reports can be found in the literature.

Objectives and methodology

In this short report, we analyze the ABO/Rh distribution in a MS cohort of 265 patients and compare these frequencies with the results obtained from the Basque Blood Donors bank (17,796 individuals) of the same region.

Results and conclusions

From our data, the absence of immune antigens (A, B or Rhesus +) defined by the group O- seems to be protective in the MS group with an odds ratio of 0.49 (95% confidence interval 0.309–0.796), while the presence of Rh+ plus A or B seems to be a risk in developing multiple sclerosis.

Association of ABO blood types and novel obesity markers in healthy adolescents

INTRODUCTION

Association of ABO blood type with body mass index (BMI) was explored in the past studies, but literature on association of novel obesity markerssuch as total body fat and lean body mass (LBM) is scarce. The present study aimed to evaluate the relationship of ABO blood types with novel obesity markers in normal adolescents.

MATERIALS AND METHODS

A cross-sectional study was done on 387 medical students. Bio-impedance analysis (BIA)-derived novel obesity markers such as body fat percent (BFP) and lean body mass (LBM) were recorded. Blood typing was done using slide-agglutination method. Mean and SD were calculated; analysis of variance and Chi-square (χ²) correlation were used to determine the relationship between ABO blood types and obesity markers.

RESULTS

Highest propensity for BFP and LBM was seen in blood groups AB and B (25.09 ± 8.92 and 44.45 ± 6.91) respectively. Highly significant (P < 0.001) differences were observed in the values of BFP and LBM in normal and obese participants across ABO blood types. Prevalence of obesity did not show significant relationship (χ² = 2.069; P = 0.913) with ABO blood types.

CONCLUSIONS

Unlike BMI, novel obesity markers (BFP and LBM) significantly differ across ABO blood groups in normal and obese population. The findings suggest that ABO blood type might have role in determining body composition. This will be helpful in recognition of the participants at the risk of obesity on the basis of their blood groups.